‘Dev Watercooler’ is a blog series that provides an inside look into the thoughts and discussions happening within the World of Warcraft development team. In our first entry, Lead Systems Designer Greg "Ghostctrawler" Street laid down a few ground rules:

1. No promises are being made in these Dev Watercooler blogs.

2. Don’t read too much between the lines.

3. No complaints about the topic not being what you want to see covered.

Are spellcast interrupt abilities, such as Kick, too good? It’s easy to make that argument. We think their ease of use and low cooldown has led to a whole cascade of events in PvP. Because interrupts are so good, casters without a lot of instant spells or mobility are weak. For that reason, we tend to give casters a lot of instant spells or movement abilities, and casters who excel at those (say, Frost mages) are very powerful, while those without (say, Elemental shaman) have more difficulty.

Because interrupts are good, classes without them feel uncompetitive, which has led to us giving interrupts to paladins and druids, which in turn has led to them being even more prevalent. Because casters tend to fire off lots of instant spells while jumping around, melee can be really easy to kite. Because melee can be easy to kite, melee classes without strong mobility can suffer, and we have to consider giving high mobility to all melee, which increases the amount of uptime melee have on casters, which means we have to give casters even more powerful escape mechanisms to survive... and the arms race continues.

See where I’m going with this? Because instant spells tend to be so powerful, we have to make cast time spells insanely powerful to compete or they’ll never see use in PvP. But we have to make those spells so powerful that when they do get off, we can have PvP burst issues. (Look at how much better Frostbolt has to be than Ice Lance for mages to even consider the “long” cast.)

Nerfing all of the interrupts across the board isn’t the kind of thing we can realistically do mid-expansion. Anyone working on the raid content can tell you how important interrupts are to today's encounter design. We’d have to redesign nearly all of the raid encounters and many of the dungeon encounters as well. Of course once you increase the cooldown on interrupts, then availability of stuns gains relative power, so you have that balance consideration as well.

Instant spells do have their place in the game. If you’re worried about being interrupted because someone is chasing you, or you are chasing them, that’s a great time to use an instant spell. But actual 2.5 sec cast time spells need to have their place too and, if anything, they should be the norm.

Here's one other way in which interrupts have wide-reaching effects on the game via the chain of consequences discussed above. One of the advantages melee used to have in PvE was on movement fights. If the boss has to be kited or stays in motion, the rogues and warriors can follow along and still deal damage. It will be less damage for sure, but they’ll still get a lot of auto attacks in. It used to be the case that asking the Balance druid or Fire mage to move was a huge dps loss for them, because they were always interrupting their spells. In today’s PvE environment, that role has almost flipped. Many casters can shoot on the run and take only a very minimal DPS hit to do so. For this reason (and a few others) melee classes can feel like a liability on certain encounters. We’d prefer for raids to want a fairly even distribution of ranged to melee classes and ideally groups would have a lot of flexibility in who they bring. It’s okay to have fights that are really good for casters, but there need to be at least a couple that feel great for melee as well.

Is there a design lesson to learn here? I guess it’s some variant of the butterfly effect -- apparently innocuous designs (in this case the short cooldown on interrupt abilities) can have wide-ranging effects on all aspects of the game. I’m not sure what the game would look like if Pummel and Kick and Wind Shear had 30 second cooldowns. Clearly we’d have to redesign a lot of other abilities, mechanics, and numbers to make it work. Again, this isn’t a change you’ll see anytime soon. But it might feel better in the long run if we could get to that point.

Greg “Ghostcrawler” Street is the lead systems designer on World of Warcraft. He knows how to get to R’lyeh.

They probably work towards that 30 sec cooldown on interrupt for next expansion, but hopefully if they do they change all encounters that need interrupts so you can do them still after the change. Fights such as Nefarian will be impossible if you have a 30 second interrupt :P

See, there was something the Devs said pre-Cata about development. They said they wanted to end the whole "tank takes massive damage spike" design style and normalize PvE damage.

Then we got to Cata, and what happened? On one of the first bossfights of the xpac in the dungeons (naga priestess in Throne) she has a one-hit killer that *has* to be interrupted. (I am aware, before you smart-arses reply saying "Oh I can soak that hit now it's no big" that gear has since trivialized it, for a large part. BUT, at the time, when the content was relevant, it was a death sentence.)

Long story short--Interrupt mechanics on bossfights really aren't that fun, especially when they require a rotation (Nefarian 25, looking back at General Vex in Ulduar, sometimes Halfus Wyrmbreaker 10&25) or when the survival of the entire raid hinges on them. When interrupt mechanics ARE fun in PvE is when they're a sort of "bonus" thing--like interrupting caster adds in Stonecore that stops them from xforming, or stopping a boss from casting a shadowbolt (which wouldn't kill anybody, but it's fun to do!).

TL;DR: Interrupting in PvE is fun when it's something skilled players can do as a bonus, NOT when all dpsers MUST do as a requirement. I don't give a rip about PvP "balance," I've long since given up on that.

Is there a design lesson to learn here? I guess it’s some variant of the butterfly effect -- apparently innocuous designs (in this case the short cooldown on interrupt abilities) can have wide-ranging effects on all aspects of the game.

No, the lesson is that you need a strong theoretical foundation for your game. Otherwise you end up a huge mess of fix upon fix and a game that never has real balance (like WoW PvE).

Interesting stuff. What about a cast time on interrupts, say 0.5s? That way you're not punishing raiders for missing interrupts (so long as the boss casts they're interrupting are at least couple of seconds long), and melee in PvP has to sacrifice some mobility for a moment?

See, there was something the Devs said pre-Cata about development. They said they wanted to end the whole "tank takes massive damage spike" design style and normalize PvE damage.

Then we got to Cata, and what happened? On one of the first bossfights of the xpac in the dungeons (naga priestess in Throne) she has a one-hit killer that *has* to be interrupted. (I am aware, before you smart-arses reply saying "Oh I can soak that hit now it's no big" that gear has since trivialized it, for a large part. BUT, at the time, when the content was relevant, it was a death sentence.)

Long story short--Interrupt mechanics on bossfights really aren't that fun, especially when they require a rotation (Nefarian 25, looking back at General Vex in Ulduar, sometimes Halfus Wyrmbreaker 10&25) or when the survival of the entire raid hinges on them. When interrupt mechanics ARE fun in PvE is when they're a sort of "bonus" thing--like interrupting caster adds in Stonecore that stops them from xforming, or stopping a boss from casting a shadowbolt (which wouldn't kill anybody, but it's fun to do!).

TL;DR: Interrupting in PvE is fun when it's something skilled players can do as a bonus, NOT when all dpsers MUST do as a requirement. I don't give a rip about PvP "balance," I've long since given up on that.

Interrupts are just another mechanic of raiding. Your argument is the same as me saying "Having to avoid standing in fire isn't fun. I should be able to stand in it if I want to. If I feel like avoiding it I could but it shouldn't kill me if I stand in it."

Also, a boss that has a mechanic that is designed to be interrupted that kills you when you fail at that mechanic has nothing to do with Blizzard's design goals of tanks not getting two shot. On this boss, if your tank dies, it's because you fail at executing the fight properly.

hmm you mean like hunters having 1 interupt on a 30 second cd, That they have to spec deep into the MM tree just to be able to use?
gosh, it is a wonder why hunters have been the least represented class in arenas since season 1.

The solution is quite simple, although would surely ruffle afew feathers. Casters are at a disadvantage because their main weapon (spells) can be interupted/silenced by every melee class and leaves them basically defenseless. The solution would be to give at least one spec of each spell casters a disarm. Demo locks could have a disarm on their felguard, fire mages could heat the handle of a hilt and force it to be disarmed, ele shammies could shock the weapons free, and Spriests have one. If all melee can take the main weapon of casters (spells) away, then casters should be able to do the same and disarm the melee's weapons for a short period of time. Yin to the Yang, and balance to the force it would bring. Right now it's a one sides battle with melee having the advantage and most casters being unable to return the favor